Umbrella hub



FIG. 1 is a first perspective view of an umbrella hub.

FIG. 2 is a second perspective view of the umbrella hub of FIG. 1;

FIG. 3 is a bottom view of the umbrella hub of FIG. 1;

FIG. 4 is a top view of the umbrella hub of FIG. 1; and,

FIG. 5 is a right side view of the umbrella hub of FIG. 1, the left, front, and back side views being the same as the right side view.

The broken lines depict portions of the article that form no part of the claimed design. 

CLAIM I claim the ornamental design for an umbrella hub, as shown and described. 